1 files changed, 15 insertions, 19 deletions

diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c
index a5b4134..cb982a6 100644
--- a/net/ipv4/esp4.c
+++ b/net/ipv4/esp4.c
@@ -1,3 +1,5 @@
+#define pr_fmt(fmt) "IPsec: " fmt
+
 #include <crypto/aead.h>
 #include <crypto/authenc.h>
 #include <linux/err.h>
@@ -457,28 +459,22 @@ static u32 esp4_get_mtu(struct xfrm_state *x, int mtu)
 	struct esp_data *esp = x->data;
 	u32 blksize = ALIGN(crypto_aead_blocksize(esp->aead), 4);
 	u32 align = max_t(u32, blksize, esp->padlen);
-	u32 rem;
-
-	mtu -= x->props.header_len + crypto_aead_authsize(esp->aead);
-	rem = mtu & (align - 1);
-	mtu &= ~(align - 1);
+	unsigned int net_adj;
 
 	switch (x->props.mode) {
-	case XFRM_MODE_TUNNEL:
-		break;
-	default:
 	case XFRM_MODE_TRANSPORT:
-		/* The worst case */
-		mtu -= blksize - 4;
-		mtu += min_t(u32, blksize - 4, rem);
-		break;
 	case XFRM_MODE_BEET:
-		/* The worst case. */
-		mtu += min_t(u32, IPV4_BEET_PHMAXLEN, rem);
+		net_adj = sizeof(struct iphdr);
+		break;
+	case XFRM_MODE_TUNNEL:
+		net_adj = 0;
 		break;
+	default:
+		BUG();
 	}
 
-	return mtu - 2;
+	return ((mtu - x->props.header_len - crypto_aead_authsize(esp->aead) -
+		 net_adj) & ~(align - 1)) + (net_adj - 2);
 }
 
 static void esp4_err(struct sk_buff *skb, u32 info)
@@ -706,11 +702,11 @@ static const struct net_protocol esp4_protocol = {
 static int __init esp4_init(void)
 {
 	if (xfrm_register_type(&esp_type, AF_INET) < 0) {
-		printk(KERN_INFO "ip esp init: can't add xfrm type\n");
+		pr_info("%s: can't add xfrm type\n", __func__);
 		return -EAGAIN;
 	}
 	if (inet_add_protocol(&esp4_protocol, IPPROTO_ESP) < 0) {
-		printk(KERN_INFO "ip esp init: can't add protocol\n");
+		pr_info("%s: can't add protocol\n", __func__);
 		xfrm_unregister_type(&esp_type, AF_INET);
 		return -EAGAIN;
 	}
@@ -720,9 +716,9 @@ static int __init esp4_init(void)
 static void __exit esp4_fini(void)
 {
 	if (inet_del_protocol(&esp4_protocol, IPPROTO_ESP) < 0)
-		printk(KERN_INFO "ip esp close: can't remove protocol\n");
+		pr_info("%s: can't remove protocol\n", __func__);
 	if (xfrm_unregister_type(&esp_type, AF_INET) < 0)
-		printk(KERN_INFO "ip esp close: can't remove xfrm type\n");
+		pr_info("%s: can't remove xfrm type\n", __func__);
 }
 
 module_init(esp4_init);